stun/rand.c

   1 /*
   2  * This file is part of the Nice GLib ICE library.
   3  *
   4  * (C) 2008 Collabora Ltd. All rights reserved.
   5  *  Contact: Youness Alaoui
   6  * (C) 2008 Nokia Corporation. All rights reserved.
   7  *
   8  * The contents of this file are subject to the Mozilla Public License Version
   9  * 1.1 (the "License"); you may not use this file except in compliance with
  10  * the License. You may obtain a copy of the License at
  11  * http://www.mozilla.org/MPL/
  12  *
  13  * Software distributed under the License is distributed on an "AS IS" basis,
  14  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  15  * for the specific language governing rights and limitations under the
  16  * License.
  17  *
  18  * The Original Code is the Nice GLib ICE library.
  19  *
  20  * The Initial Developers of the Original Code are Collabora Ltd and Nokia
  21  * Corporation. All Rights Reserved.
  22  *
  23  * Alternatively, the contents of this file may be used under the terms of the
  24  * the GNU Lesser General Public License Version 2.1 (the "LGPL"), in which
  25  * case the provisions of LGPL are applicable instead of those above. If you
  26  * wish to allow use of your version of this file only under the terms of the
  27  * LGPL and not to allow others to use your version of this file under the
  28  * MPL, indicate your decision by deleting the provisions above and replace
  29  * them with the notice and other provisions required by the LGPL. If you do
  30  * not delete the provisions above, a recipient may use your version of this
  31  * file under either the MPL or the LGPL.
  32  */
  33
  34
  35
  36 #ifdef HAVE_CONFIG_H
  37 # include <config.h>
  38 #endif
  39
  40 #include "rand.h"
  41
  42
  43 #ifdef _WIN32
  44
  45 #include <windows.h>
  46 #include <wincrypt.h>
  47
  48 void RAND_bytes (uint8_t *dst, int len)
  49 {
  50   HCRYPTPROV hCryptProv;
  51   LPCSTR container = "Libnice key container";
  52
  53   if(!CryptAcquireContext(&hCryptProv, container, NULL, PROV_RSA_FULL, 0)) {
  54     /* non existing container. try to create a new one */
  55     // I hope this cast here doesn't cause issues
  56     // gcc was complaining about comparing signed and unsigned values
  57     if (GetLastError() == (DWORD) NTE_BAD_KEYSET) {
  58       if(!CryptAcquireContext(&hCryptProv, container, NULL, PROV_RSA_FULL, CRYPT_NEWKEYSET)) {
  59         return;
  60       }
  61     }
  62     return;
  63   }
  64
  65   CryptGenRandom (hCryptProv, len, dst);
  66
  67   CryptReleaseContext(hCryptProv,0);
  68 }
  69 #else
  70
  71 /* ------------- Start original implementation. ----------------- */
  72 /* http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/MT2002/emt19937ar.html */
  73
  74 /*
  75    A C-program for MT19937, with initialization improved 2002/1/26.
  76    Coded by Takuji Nishimura and Makoto Matsumoto.
  77
  78    Before using, initialize the state by using init_genrand(seed)
  79    or init_by_array(init_key, key_length).
  80
  81    Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
  82    All rights reserved
  83
  84    Redistribution and use in source and binary forms, with or without
  85    modification, are permitted provided that the following conditions
  86    are met:
  87
  88      1. Redistributions of source code must retain the above copyright
  89         notice, this list of conditions and the following disclaimer.
  90
  91      2. Redistributions in binary form must reproduce the above copyright
  92         notice, this list of conditions and the following disclaimer in the
  93         documentation and/or other materials provided with the distribution.
  94
  95      3. The names of its contributors may not be used to endorse or promote
  96         products derived from this software without specific prior written
  97         permission.
  98
  99    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 100    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 101    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 102    A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 103    CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 104    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 105    PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 106    PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 107    LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 108    NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 109    SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 110
 111
 112    Any feedback is very welcome.
 113    http://www.math.sci.hiroshima-u.ac.jp/~m-mat/MT/emt.html
 114    email: m-mat @ math.sci.hiroshima-u.ac.jp (remove space)
 115 */
 116
 117 /* Period parameters */
 118 #define N 624
 119 #define M 397
 120 #define MATRIX_A 0x9908b0dfUL   /* constant vector a */
 121 #define UPPER_MASK 0x80000000UL /* most significant w-r bits */
 122 #define LOWER_MASK 0x7fffffffUL /* least significant r bits */
 123
 124 static unsigned long mt[N]; /* the array for the state vector  */
 125 static int mti=N+1; /* mti==N+1 means mt[N] is not initialized */
 126
 127 /* initializes mt[N] with a seed */
 128 static void init_genrand(unsigned long s)
 129 {
 130   mt[0]= s & 0xffffffffUL;
 131   for (mti=1; mti<N; mti++) {
 132     mt[mti] = (1812433253UL * (mt[mti-1] ^ (mt[mti-1] >> 30)) + mti);
 133     /* See Knuth TAOCP Vol2. 3rd Ed. P.106 for multiplier. */
 134     /* In the previous versions, MSBs of the seed affect   */
 135     /* only MSBs of the array mt[].                        */
 136     /* 2002/01/09 modified by Makoto Matsumoto             */
 137     mt[mti] &= 0xffffffffUL;
 138     /* for >32 bit machines */
 139   }
 140 }
 141
 142 /* initialize by an array with array-length */
 143 /* init_key is the array for initializing keys */
 144 /* key_length is its length */
 145 /* slight change for C++, 2004/2/26 */
 146 static void init_by_array(unsigned long init_key[], int key_length)
 147 {
 148   int i, j, k;
 149   init_genrand(19650218UL);
 150   i=1; j=0;
 151   k = (N>key_length ? N : key_length);
 152   for (; k; k--) {
 153     mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1664525UL))
 154         + init_key[j] + j; /* non linear */
 155     mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
 156     i++; j++;
 157     if (i>=N) { mt[0] = mt[N-1]; i=1; }
 158     if (j>=key_length) j=0;
 159   }
 160   for (k=N-1; k; k--) {
 161     mt[i] = (mt[i] ^ ((mt[i-1] ^ (mt[i-1] >> 30)) * 1566083941UL))
 162         - i; /* non linear */
 163     mt[i] &= 0xffffffffUL; /* for WORDSIZE > 32 machines */
 164     i++;
 165     if (i>=N) { mt[0] = mt[N-1]; i=1; }
 166   }
 167
 168   mt[0] = 0x80000000UL; /* MSB is 1; assuring non-zero initial array */
 169 }
 170
 171 /* generates a random number on [0,0xffffffff]-interval */
 172 static unsigned long genrand_int32(void)
 173 {
 174   unsigned long y;
 175   static unsigned long mag01[2]={0x0UL, MATRIX_A};
 176   /* mag01[x] = x * MATRIX_A  for x=0,1 */
 177
 178   if (mti >= N) { /* generate N words at one time */
 179     int kk;
 180
 181     if (mti == N+1)   /* if init_genrand() has not been called, */
 182       init_genrand(5489UL); /* a default initial seed is used */
 183
 184     for (kk=0;kk<N-M;kk++) {
 185       y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
 186       mt[kk] = mt[kk+M] ^ (y >> 1) ^ mag01[y & 0x1UL];
 187     }
 188     for (;kk<N-1;kk++) {
 189       y = (mt[kk]&UPPER_MASK)|(mt[kk+1]&LOWER_MASK);
 190       mt[kk] = mt[kk+(M-N)] ^ (y >> 1) ^ mag01[y & 0x1UL];
 191     }
 192     y = (mt[N-1]&UPPER_MASK)|(mt[0]&LOWER_MASK);
 193     mt[N-1] = mt[M-1] ^ (y >> 1) ^ mag01[y & 0x1UL];
 194
 195     mti = 0;
 196   }
 197
 198   y = mt[mti++];
 199
 200   /* Tempering */
 201   y ^= (y >> 11);
 202   y ^= (y << 7) & 0x9d2c5680UL;
 203   y ^= (y << 15) & 0xefc60000UL;
 204   y ^= (y >> 18);
 205
 206   return y;
 207 }
 208
 209 /* These real versions are due to Isaku Wada, 2002/01/09 added */
 210
 211 /* ------------- End original implementation. ----------------- */
 212
 213 #include <stdio.h>
 214 #include <time.h>
 215
 216 static int initialized = 0;
 217
 218 void RAND_bytes (uint8_t *dst, int len)
 219 {
 220   int i;
 221
 222   if (!initialized) {
 223     /* Seed the generator with an array from /dev/urandom if available
 224        Otherwise use time() and clock() values */
 225
 226     FILE *urandom = fopen( "/dev/urandom", "rb" );
 227     unsigned long init_key[10] = {};
 228     int key_length = 0;
 229     if (urandom) {
 230       while (fread(&init_key[key_length++], sizeof(unsigned long), 1,
 231               urandom) > 0 &&    key_length < 10);
 232       fclose(urandom);
 233     } else {
 234       time_t t = time (NULL);
 235       clock_t c = clock ();
 236       unsigned long cl = c;
 237       unsigned long tl = t;
 238       init_key[0] = *((unsigned long *) dst);
 239       init_key[1] = 0x6c69626e;
 240       init_key[2] = 0x69636500;
 241       init_key[3] = tl;
 242       init_key[4] = cl;
 243       key_length = 5;
 244     }
 245     init_by_array(init_key, key_length);
 246     initialized = 1;
 247   }
 248
 249   for (i = 0; i < len; i++) {
 250     dst[i] = genrand_int32 () & 0xFF;
 251   }
 252 }
 253
 254 #endif /* _WIN32 */